核糖蛋白替代鱼粉对大菱鲆幼鱼生长性能、肠道消化酶活性、免疫能力及血清生化指标影响

Effects of Partial Replacement of Fish Meal with Ribose Protein on Growth Performance, Intestinal Digestive Enzyme Activities, Specific Immune Indices and Physiological and Biological Indices of Juvenile Turbot (Scophthalmus maximus L.)

中文关键词: 核糖蛋白  大菱鲆  生长性能  消化酶活性  血清生化指标

英文关键词: Ribose protein  Scophthalmus maximus L.  Growth performance  Activity of intestinal enzymes  Physiological and biological indices

中文摘要:

      本研究旨在评价核糖蛋白替代大菱鲆(Scophthalmus maximus)饲料中鱼粉的潜力。采用单因素实验设计，设6个鱼粉替代水平。对照饲料(D1)中鱼粉含量为45%，通过添加核糖蛋白替代D1组饲料中鱼粉的0.5% (D2)、1% (D3)、2% (D4)、3% (D5)和4% (D6)。实验期间，每天分2次按饱食量投喂初始体重为(24.00±0.30) g大菱鲆幼鱼56 d。结果显示，幼鱼增重率、特定生长率、蛋白质效率随着核糖蛋白替代水平的变化呈先上升后下降趋势，均在D3组达到最高值，显著高于D5和D6组(P<0.05)；饲料系数则呈相反趋势，在D3组达到最低值，显著低于D6组(P<0.05)。各替代组幼鱼血清胰岛素生长因子(IGF-1)和生长激素(GH)含量均显著低于对照组(P<0.05)；核糖蛋白替代1%~3%的鱼粉后，显著提高了幼鱼肠道胰蛋白酶活性(P<0.05)；幼鱼肠道α-淀粉酶活性在D4和D5组显著高于对照组(P<0.05)；饲料中添加核糖蛋白替代鱼粉显著降低了幼鱼肠道脂肪酶活性(P<0.05)。各替代组幼鱼血清总蛋白、球蛋白含量和碱性磷酸酶活性均显著高于对照组(P<0.05)；D3组溶菌酶活性显著高于D6组(P<0.05)；各组间幼鱼血清白蛋白含量和超氧化物歧化酶活性无显著差异(P>0.05)，但各替代组均显著提高了幼鱼血清白介素β1 (IL-1β)和肿瘤坏死因子(TNF-α)含量(P<0.05)；与对照组相比，D4~D6组血清总胆固醇和甘油三酯含量显著降低(P<0.05)，低密度脂蛋白在D5和D6组显著降低(P<0.05)；高密度脂蛋白在D4组显著升高(P<0.05)。血糖浓度呈先升高后降低的趋势，D3组显著高于对照组(P<0.05)。攻毒实验结果显示，D2组大菱鲆幼鱼48 h累积死亡率最低为56.45%。研究表明，饲料中添加核糖蛋白替代1%鱼粉时，大菱鲆幼鱼生长、消化酶活力及鱼体的免疫能力和抗细菌感染能力均达到最高。

英文摘要:

      This study was conducted to evaluate the potential of replacing fish meal with ribose protein in juvenile turbot (Scophthalmus maximus L.). A single factor experiment -with six fish meal levels was used. A control diet (D1) was formulated to contain 45% fish meal. In other five diets, 44.5% (D2), 44% (D3), 43% (D4), 42% (D5), and 41% (D6) of the fish meal in the diet control were replaced with ribose protein, respectively. Each diet was randomly fed to triplicate groups of 30 fish per tank. The experimental period was 56 d. The results showed that as the replacement ratio of fish meal by ribose protein increased, the weight gain rate (WG), specific growth rate (SGR), and protein efficiency ratio (PER) showed a trend of first rising and then decreasing, they were all significantly higher in the D3 group than in the D5 and D6 groups (P<0.05). However, the feed conversion ratio reached a minimum in the D3 group. Compared with the control group, the serum IGF-1 and GH contents in the replacement groups were significantly decreased (P<0.05). Trypsin activities of the intestine in D3, D4, and D5 groups were significantly higher than in other groups (P<0.05). Amylase activities in the intestine of the D3 and D4 groups were significantly higher than that in the control group (P<0.05). Lipase activity reached a minimum in the D3 group (P<0.05). The total protein, globulin, and alkaline phosphatase contents in the replacement groups were significantly higher than those in the control group (P<0.05). The lysozyme activity in the D3 group was significantly higher than that in the D6 group (P<0.05). The albumin content and the activity of superoxide dismutase were not significantly different among all the groups (P>0.05), while the serum IL-1β and TNF-α contents were significantly increased (P<0.05). Compared with the control group, the total cholesterol and triglyceride contents in the D4, D5, and D6 groups were significantly decreased (P<0.05). The serum low-density lipoprotein cholesterol content of the D5 and D6 groups was significantly decreased (P<0.05), and the serum high-density lipoprotein cholesterol content of the D4 group was significantly increased (P<0.05). Glucose content first increased and then decreased as the replacement ratio of fish meal by ribose protein increased, and it was the highest in the D3 group (P<0.05). The challenge study showed that the D2 group had a lower cumulative mortality rate than other groups after 48 hours (P<0.05). It can be concluded that the optimum level of replacing fish meal in turbot diet with ribose protein is 1% based on growth performance, and simultaneously considers the indices of digestion and specific immune, and disease resistance in S. maximus under this experimental condition.